This application seeks support for renewal of a multidisciplinary training program in Pediatric Gastroenterology research. The specific aim of the program is training of postdoctoral candidates in basic research in order to prepare them for independent academic careers in pediatric gastrointestinal and hepatic sciences. The program involves 2-3 years of laboratory-based investigation and emphasizes the application of modem cell and molecular biologic approaches to addressing fundamental issues in pediatric gastroenterology and development of gastrointestinal and hepatic function. Training originates from the Department of Pediatric which in the last 10 years has attracted 80 new full time faculty members, most of whom have deep commitments to academic careers involving research. Many disciplines are represented in the training faculty including Biochemistry, Cell Biology and Physiology, Molecular Biology and Pharmacology, Immunology, Molecular Microbiology and Genetics. Members of the faculty have common interests, have frequent interactions, have a tradition of scholarly excellence in basic science, a tradition of establishing independent funded research careers and a penchant for working beyond the narrow boundaries of their own disciplines/research areas/specialties. Ample space and facilities are available and, by interdigitation with other training activities existing within the institution, the program avails itself of the rich educational activities including didactic coursework and seminars in basic sciences, biostatistics and research ethics. A 'Project Committee' for each trainee functions like a Thesis Advisory Committee in basic science graduate training programs. Trainees work side-by-side in a laboratory with other M.D., Ph.D. and M.D./Ph.D. predoctoral and postdoctoral trainees. Based on the excellent trainees already accepted for FY01 and increasing numbers of candidates under consideration for FY02, support for 4 postdoctoral fellows per year is requested. The investigators anticipate that this will be composed of 2 fellows in their first year of laboratory training and 2 fellows in their second year of laboratory training. Because there is still a shortage of well-trained independent academic pediatric gastroenterologists, the program is primarily designed for pediatric gastrointestinal physicians, but has also trained physicians in other specialties (neonatology, surgery, nutrition) and Ph.D.s with deep commitments to gastrointestinal biology.